Spring-scale.



PATENTED JUNE 5, 1906.

G. WALKER. SPRING SCALE.

APPLICATION FILED JAN. 4, 1906.

2 SHEETS-SHEET 1.

PATENTED JUNE 5, 1906. G. WALKER.

SPRING SCALE.

APPLICATION FILED JAN.4, 1906.

JUVE/772W? Re DY ge WLKQC l I I' www Ufa/mm1' UNITED STATES PATENT OFFICE.

GEORGE VALKER, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO LAND- ERS, FRARY AND CLARK, OF NEWT BRITAIN, CONNECTICUT, A CORPO- BATION.

SPRING-SCALE.

Patented June 5, 1906.

Application filed January 4.1906x Serial No. 294,541.

T all whom, it may concern.-

Be it known that I, GEORGE WALKER, a citizen of the United States, residing at New Britain, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Spring-Scales, of which the following is a specification.

My invention relates to improvements in spring-scales and the objects of my improvements are simplicity and economyT in construction and convenience and eiiiciency in use.

In the accompanying drawings, Figure 1 is a sectional front elevation of a scale embodying one form of my improvement, some of the parts being broken away, while the dial and pointer are removed. Fig. 2 is a sectional plan of parts thereof, the plane of section being on the line Qc of Fig, 1. Fig. 3 is a detached plan view of the draw-bar. Fig. 4 is a detached front elevation of the upper part of the scale with the preferred form of hanger substituted for that shown in Fig. 1. Fig. 5 is a detached plan view of the said hanger. Fig. 6 is a detached vertical section, partly in elevation, of a portion of the checking-cylinder with a modified form of the inner end of the piston.

A designates the frame of the case, having the partial back 6, upon which to place diiferent parts, including the pivotal stud or post 7, upon whichto mount either the hangerlever S of the said Fig. 1 or the hanger-lever 8a of Figs. 4 and 5. The right-hand end of the hanger-lever 8 cornes near the central vertical line of the frame A, and to this end is pivoted 0n the pin 9 the hanger-frame 10. In the left-hand end of the hanger-lever is a tumbler-iiut or pivoted block 11, having a threaded hole extending transversely through it, into which one end of the tare-adjusting screw or rod 12 is fitted, the other end of the said rod passing through the frame to the exterior of the case, where it is provided with a handle 13, which, as shown in Fig. 1, is at the lower part of the frame, This screw or rod, while free to rotate in the frame, is held against longitudinal movement by any suitable or ordinary means-as, for example, by the collar 14, either with or without the interposed spring 15.

The ordinary counterbalancing-springs 16 are hung to the hanger-frame in an adjustable manneras, for example, by theL screw-eyes 17-while the lower ends of the said springs are secured in any proper manner to the cross-head 19 of the draw-bar 20. As shown, the springs 16 are connected to the said cross-head by means of the iianged studs 21, upon which the lower ends of the springs are screwed. The draw-bar 2() is provided at its lower end with any ordinary means for supporting a load-as, for example, the hook 22. As shown, it is also provided with scaleplates 23, which, however, form no part of the present invention. The cross-head 19 is in the form of a frame composed of upper and lower members with connected ends, and to the lower member the lower end of the rack 24 is pivoted at 25, the said rack extending upwardly through a hole 26 in the upper member of the cross-head 19. The ordinary pointer or index-pinion 27 is mounted on a shaft 28, one end of which shaft is mounted in the partial back 6, while the other end has its bearing in the bracket 29, which is represented in Fig. 1 as broken off, so as to show the pinion. A guard or guide 30 for the back edge of the rack is also mounted on the partial back 6. The rack which engages the pinion 27 is held gently in engagement therewith by means of the spring 31, that liesin the open frame of the cross-head 19, with one end secured to the said rack and its other end adjustably held in the end 34 of the crosshead by means of the screw 32, to which that end of the said spring is secured, and the two set-nuts 33 on opposite sides of the end 34 of the said cross-head, through which end the said screw passes.

The scale thus far described is complete and operative but for large scales it is desirable to cushion the action of the springs 16 so as t0 bring the pointer or other moving index quickly to rest. To this end the checking-cylinders 35 are loosely pivoted or hung to the hanger-frame by means of theeyes 36 and pins 37 l/Vith each of these cylinders a hollow piston 38 or piston-cylinder is fitted with a close but easy fit, and its lower end is connected in like manner to the upper member of the cross-head 19 by the eyes 39. The fit 0f the piston and cylinders is so nearly airtight that when moved suddenly in either direction they have a tendency to check the motion of the draw-bar, and yet the fit is so loose that the piston moves easily at the start and after checking the air will eventually IOO for the rack is conveniently applied and adleak in or out between the cylinder and piston to relieve the checking eect.

In the construction shown in Figs. 1 and 2 the hanger consists of the hanger-lever and connected hanger-frame. In Figs. 4 and 5 it consists of the hanger-lever 8a, the hangerframe 10a, and the parts by which the said lever and frame are connected. They are Vboth hung or mounted upon the stud or post 7 of the frame and are both adapted to receive the same springs, cylinders, and tare-adjusting screw without any change whatever in the construction of the other parts, excepting to form the hole and seat for the tare-adjusting screw at the top or bottom of the frame A, as shown, respectively, in Figs. l and 4, accordingly to whether the long tareadjusting screw 12 or the short tare-adjusting screw 12a is employed. The operation is the same in either case. 'Thehanger-lever 8a is provided 'with a resilient rod-like arm 40, that passes loosely through a trunnion-block 4l, to which the hanger-frame 10a is hung. Thistrunnion-block has a anged stud 42 at its right-hand side or end, to which one end of an equalizing device 4S is screwed or otherwise secured. This equalizer surrounds the arm 40, which is substantially horizontal, and the end oi the equalizer that is Jfarthest from the trunnion-block is made fast to the said arm in any proper manner-as, for example, by means of a ilanged hub 44 and set-screw 45. The hanger-frame l0EL has the same parts secured to it as does the hanger-frame 10, and they may be secured in the same way. The rod-like arm and connected parts are designed as an equalizer to automatically adjust the scale for weighing accurately in all ordinary temperatures. It accomplishes this object by changing the eective leverage of the resilient arm 40. The hanger-lever when adjusted is firmly held or fixed in place, so that the eiiect is substantially the same on the resilient arm 40 as if the said arm were mounted by one end yrigidly to the frame or case of the scale. Ii the temperature is low, the equalizing device 43 contracts and draws the trunnion block and attached hanger-frame toward the right, thereby shifting its position on the resilient arm 40 and increasing the effective length of the portion between the suspended hanger-frame and the rigid connection of the said arm with the main frame or case. Upon a rise of temper ature the effective length of the resilient arm is decreased.

Mounting the hanger-frame on a hangerlever ofthe main frame or case permits of the application to the scales of the tare-adjusting screw to change the eiective length of the counterbalancing-springs in the simple and eiiicient manner herein shown and described. By the particular construction of the crosshead of the draw-bar the adjustable spring justed, and at the same time ample provision is made for connecting the lower end of a piston or cylinder to the said crosshead without having the said parts interfere with each other. By the employment of a cylindrical piston or a hollow piston iitting substantially the length of the cylinder both ends of the combined cylinder and piston may be loosely attached and an eliicient airvcushion or check produced. A

By the employment of a hollow cylinder for the piston both the cylinder and piston may be made of tubing, whereby a long pis tonmaybe employed that fits the cylinder for substantially its whole length and without making the piston so heavy as not to be easily moved. Vhen the inner end of the piston is open, as shown in Fig. l, so that the inclosed air-cushion within the cylinder is substantially as long as the cylinder, a very elastic and easy cushion is provided which is particularly adapted for pointer-scales or scales in which the pinion-shatis not heavily loaded, and even with a heavily-loaded pinion-shaft the elasticityof the cushion removes the severe strain from the pinion. By having a central depression or opening in the inner end of the piston whatever dust may be inclosed within the cylinder is less liable to Work in between the cylinder and piston than would be the case if the inner end of the piston were not thus recessed. For a heavily-loaded pinion-shaft, asl in computing-sca es having aV cylinder on the pinionpshaft, I prefer the construction shown in Fig. 6, in which the inner end of the piston 38"i is closed by a plug or cap 50, preferably with a dust-pocket 5l in its face. The dust-pocket also forms a part of the cushion, and the saidcushion may be made more or less elastic for different kinds of scales by varying the depth of the pocket, a shallow pocket being shown in Fig. 6 and a deep ocket in Fig. l.'

I c aim as my invention- 1. In a spring-scale, the combination `of a main frame with a hanger-lever pivotally mounted thereon, a hanger-frame pivotally mounted on the said hanger-lever and in substantially the same plane therewith, a pair of counterbalancing-springs hung on the said hanger-frame in an adjustable manner and in the plane of the said hanger-frame and hanger-lever, and means for adjusting the said hanger-lever to vary the height of the said hanger-frame and its adjustably-connected springs.

2. In a spring-scale, the combination of a frame with a hanger-lever pivotally mounted thereon, a hanger-frame mounted on the said lever for suspending the counterbalancing-springs, a tumbler-nut in the said hangerlever, and an adjusting-screw mounted in the said case and nut for changing the position of the said hanger-frame.

3. In a spring-scale, the combination of a IOO IIO

frame or case with a substantially horizontal resilient arm made fast on the said frame by one end, a trunnion-block mounted to slide on the said arm, an equalizing device secured by one end to the said trunnion-block, means for securing the opposite end of the said equalizing device to the said resilient arm, and a hanger-frame suspended Jfrom the said trunnion-block from which to suspend the scale-springs.

4. In a spring-scale, the combination of a trame or case with a substantially horizontal and resilient arm made fast on the said frame, a hanger-frame suspended from the said resilient arm for the attachment of the counterbalancing-springs, and means connected with the said hanger-trame and arm tor moving the hanger-frame on the said arm under temperature changes, to vary the effective length of the said resilient arm.

5. In a spring-scale, the combination of a frame or case with a hanger-lever adjustably mounted and held thereon, a resilient arm mounted on the said hanger-lever and extended subst antially in a horizontal direction therefrom, a hanger-trame suspended from the said resilient arm, counterbalancing-springs suspended from the said hanger-frame, and means connected with the said hanger-frame and arm for increasing the eiiective length of the said resilient arm when the temperature falls, and decreasing it when the temperature rises.

6. In a spring-scale, the combination of a frame or case with counterbalancing-springs hung therefrom, a draw-bar having a crosshead by which it is suspended from the said springs, a pinion mounted to rotate on the said frame, a rack extending vertically for engagement with the said pinion, the said rack being pivoted by its lower end to the said cross-head, a spring secured by one end to the lower end of the said rack and byits other end to the said cross-head for forcing the rack toward its pinion, and means mounted on the said cross-head for adjusting the connection of the said spring with the said cross-head to vary the pressure of the rack against the said pinion.

7. In a spring-scale, the combination of a frame or case with counterbalancing-springs hung therefrom, a draw-bar having a crosshead suspended from the lower ends of the said springs, and a checking device consisting of a pair of hollow cylinders closed at one end and open at the other, said cylinders being iitted one within the other, with their closed ends outwardly to form one common checking-chamber inside ofthe said two cylinders, one of which cylinders is flexibly connected with the case by its upper end and the other of which is iieXibly connected with the draw-bar by its lower end.

8. In a spring-scale, the combination of a frame or case with counterbalancing-springs hung therefrom, a draw-bar suspended from the lower ends of the said springs, a checking device consisting of a cylinder and a cylindrical piston, the said piston fitting the said cylinder for substantially the whole length of the said cylinder, and having an open pocket in its inner end which forms a part of the checking-chamber, and flexible connections with the frame and draw-bar for the opposite ends ofthe said cylinder and piston.

9. In a spring-scale, the combination of a frame or case with counterbalancing-springs suspended therefrom, a draw-bar suspended from the lower ends of the said springs, and a checking device for saidl draw-bar consisting of a hollow cylinder, and a hollow cylindrical piston within the said cylinder iitting the same for substantially its whole length, and with its interior forming a part of the checking-chamber, which chamber, when the piston is at the end of its inward stroke, is several times longer than the distance between the inner end of the said piston and the confronting end wall of the said cylinders, one of the said parts being iiexibly connected with the case by its upper end and the other being flexibly connected by its lower end with the draw-bar.

10. In a spring-scale, the combination of a Jframe or case with a hanger-trame ileXibly mounted thereon, counterbalancing-springs connected by their upper ends with the said hanger-frame, a draw-bar suspended from the lower ends of the said springs, a pinion mounted on the said frame or case, a rack for engaging the said pinion, the said rack being connected with the said draw-bar, and two checking-cylinders and their pistons, the said cylinders and pistons being iiexibly connected with the said hanger-trame and drawbar.

ll. In a spring-scale, the combination of a frame or case, with a hanger-frame ilexibly mounted thereon, counterbalancing-springs connected by their upper ends with the said hanger-frame, a draw-bar having a crosshead suspended from the lower ends of the said springs, a pinion mounted on the said frame or case, a rack for engaging the said pinion, the said rack being connected with the said cross-head, checking-cylinders and pistons connected with the said hangerframe and cross-head, and a spring on the said cross-head below the lower ends ol the said cylinders and pistons, one end of the said spring being secured to the said rack and the other to the said cross-head.

GEORGE VALKER.

Witnesses:

CLARENCE G. GARRrGoN, ARTHUR J. NoRTi-iRoP, Jr.

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